/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.jms.config;

import org.springframework.jms.listener.MessageListenerContainer;
import org.springframework.lang.Nullable;
import org.springframework.util.Assert;

import javax.jms.MessageListener;

/**
 * A {@link JmsListenerEndpoint} simply providing the {@link MessageListener} to
 * invoke to process an incoming message for this endpoint.
 *
 * @author Stephane Nicoll
 * @since 4.1
 */
public class SimpleJmsListenerEndpoint extends AbstractJmsListenerEndpoint {

    @Nullable
    private MessageListener messageListener;

    /**
     * Return the {@link MessageListener} to invoke when a message matching
     * the endpoint is received.
     */
    @Nullable
    public MessageListener getMessageListener() {
        return this.messageListener;
    }

    /**
     * Set the {@link MessageListener} to invoke when a message matching
     * the endpoint is received.
     */
    public void setMessageListener(@Nullable MessageListener messageListener) {
        this.messageListener = messageListener;
    }

    @Override
    protected MessageListener createMessageListener(MessageListenerContainer container) {
        MessageListener listener = getMessageListener();
        Assert.state(listener != null, "No MessageListener set");
        return listener;
    }

    @Override
    protected StringBuilder getEndpointDescription() {
        return super.getEndpointDescription()
                .append(" | messageListener='").append(this.messageListener).append("'");
    }

}
